Noise Attenuating Headset

ABSTRACT

Systems and techniques are disclosed for a headset that may be used in an audio system used in a magnetic field. In one aspect, the system includes an inner set portion adapted to fit into an ear canal. A pneumatic port is disposed in the hole to couple audible sounds to the ear canal. The system may include a non-magnetic transducer coupled to the pneumatic port. The system also may include a fiber-optic microphone to couple sound from a user of the headset. Other techniques provide a stethoscope-type yoke to couple the pneumatic port and the fiber-optic antenna to the non-magnetic transducer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority from a U.S. ProvisionalApplication entitled “Improved Noise Attenuating Communications Headsetfor Use in a High Magnetic Field (MRI),” filed Oct. 31, 2003 withExpress Mail Label No. ER542908696US; U.S. Provisional Applicationentitled “Improved Noise Attenuating Communications Headset for Use in aHigh Magnetic Field (MRI),” filed Oct. 27, 2003 with Express Mail LabelNo. ER542908651US; U.S. Provisional Application entitled “Improved NoiseAttenuating Communications Headset for Use in a High Magnetic Field(MRI),” filed Oct. 27, 2003 with Express Mail Label No. ER542908679US;and U.S. Provisional Application entitled “Improved Noise AttenuatingCommunications Headset for Use in a High Magnetic Field (MRI),” filedOct. 27, 2003 with Express Mail Label No. ER542908665US all of which areincorporated herein by reference in their entirety.

BACKGROUND

This disclosure relates to noise-attenuating headsets for use inmagnetic fields. Magnetic resonance imaging systems (MRI) produce loudnoises associated with the drive pulses applied to the gradient coils.As MRI technology has advanced and the gradient coils have become morepowerful, the level of the sound produced has increased to a point whereit may be necessary to provide sound pressure protection for people inthe vicinity of the MRI system when the system is operating.

SUMMARY

The present application describes systems and techniques relating tonoise reduction headsets in a magnetic environment.

The technique includes a magnetically inert headset comprising an outerset portion disposed in an ear cup adapted to cover an ear. An earinsert having a through-hole is disposed in the outer set portion,wherein the inner set portion is adapted to fit into an ear canal. Apneumatic port is disposed in the hole in the inner set to coupleaudible sound waves to the ear canal.

In an implementation, the technique is facilitated by including astethoscope-type yoke to couple the pneumatic port to a non-magneticaudio transducer.

In another implementation, the technique is facilitated by including anon-magnetic microphone to enable a user of the headset to communicatewith another person. The non-magnetic microphone may be a fiber-opticmicrophone or a piezoelectric microphone.

In another aspect, the technique includes inserting an ear insert havinga through-hole into a ear canal of a user; disposing a pneumatic portinto the hole in the ear insert; coupling the pneumatic port to apneumatic tube; and coupling the pneumatic tube to an output of an audiotransducer.

Some implementations of the systems and techniques described herein mayprovide one or more of the following advantages. The system may reducethe sound level due to the operation of a magnetic device such as amagnetic resource imaging system from entering a user's ear canal. Thetechnique may enable communication to a user in a noisy environment and,in some implementations, enable the user to communicate with anotherperson.

Details of one or more implementations are set forth in the accompanyingdrawings and the description below. Other features and advantages may beapparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will now be described in detail with referenceto the following drawings.

FIGS. 1A-B are illustrations of a first embodiment of the disclosedtechnique.

FIG. 2 is an implementation of an inner set portion.

FIG. 3 is an implementation of the noise attenuation technique with apiezoelectric transducer.

FIG. 4 is an implementation of the noise attenuation technique in astethoscope-type headset.

FIG. 5 is a detail view of the yoke attachment of the stethoscope-typeheadset of FIG. 4.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The systems and techniques disclosed here relate a system for reducingnoise in a headset used in a magnetic environment. For example, MRIsystems can produce loud noises associated with drive pulses applied tothe MRI gradient coils. A headset may be used to decrease the level ofsound that a person hears while undergoing examination in, or in thevicinity of, the MRI system when the system is operating. The headsetalso may enable a user, such as a patient undergoing an MRI examination,to hear a MRI technologist while the MRI system is operating. Theheadset can be made of non-magnetic materials and includes an ear insertthat may be inserted into an ear canal to reduce the sounds heard by theuser.

FIG. 1A illustrates a noise-attenuating headset 50. The headset includesright and left ear covers 100, 52, respectively, which may have foampadding 316 to attenuate noise and cushion the ear covers when in use. Arespective ear insert 102 is disposed in each ear cover. The ear insertis adapted to fit into an ear canal of a user. The ear insert mayinclude a pneumatic port 106 to couple sound received through pneumatictubes 110. A non-magnetic microphone 54 may be provided for on theheadset. The microphone may be used to permit a user to communicate withanother person.

FIG. 1B illustrates the right-side ear cover 100. The left-side may besimilarly structured. The headset may be made of non-magnetic materialsthat are not affected by a magnetic field. The headset includes an innerset portion that may include the ear insert 102 and the pneumatic port106. The ear insert is adapted to fit into a person's ear canal 108. Inan implementation, the ear insert may be made of a material that canconform to the shape of the ear canal upon insertion therein such ascompressible foam, vinyl, plastic or rubber. The ear insert may be madein alternative sizes, shapes or materials to conform to the variationsin ear canal geometry of different users. Placing the insert within theear canal so that it substantially conforms to the shape of the earcanal can attenuate the noises that may be created by the gradient coilsof a MRI system. An adapter 104 may be used to support the pneumaticport and can couple the port to pneumatic tubing 110. The pneumatictubing 110 can be used to carry sounds from the output of an audiotransducer (not shown). The inner set portion may be disposed within anouter set portion, which includes an ear cup 116. The ear cup 116 maycome in different sizes to accommodate different sizes of ears. In animplementation, the ear cup 116 may be provided with a removable accesspiece 112 to provide access to the inner set portion through an outersurface of the ear cup 116.

FIG. 2 illustrates an implementation of an inner set portion 200comprising the ear insert 102 and the pneumatic port 106. The ear insert102 has a through-hole 204. The pneumatic port 106 may be in the form ofa hollow tube and disposed within the ear insert hole 204. The pneumaticport 106 can provide coupling of sound to the ear canal withoutsubstantially disturbing the contact between the ear insert and earcanal walls. In an implementation, the ear insert 102 may be intendedfor disposal after each use for various reasons such as for sanitarypurposes. The adapter 104 may be used to couple the pneumatic port 106to the pneumatic tube 110. In an implementation, the adapter may have aconical opening 206 to help guide the pneumatic port 106 into thepneumatic tube 110. The adapter may comprise a gasket 202 such as anO-ring disposed in the adapter to support, retain or help seal thepneumatic port 106 in the adapter 104.

In an implementation, a non-magnetic microphone may be coupled to theheadset to enable communication between the headset wearer and anotherperson. For example, in a MRI system, a user may wear the headset andcommunicate with the system operator. Non-magnetic microphones includenoise-canceling fiber-optic and piezoelectric microphones. Themicrophone may be coupled to the headset by a non-magnetic mount. Anoptical fiber associated with the microphone may be routed adjacent thepneumatic tubes to provide connection to the microphone.

The pneumatic port 106 may be placed in the hole 204 of the ear insert102. A first end of the pneumatic tubing 110 may be coupled to thepneumatic port 106. A second end of the pneumatic tubing may be coupledthe output of an audio transducer (not shown). The audio transducer maybe located in the magnet room of a MRI system. The ear insert 102 may bedisposed in the ear canal. In an implementation, there is an adapter 104having a conical opening on a first end. The conical adapter is disposedwithin the ear cup 116 such that when the headset is placed over theears, the conical opening guides the pneumatic port 106 into thepneumatic tubing 110. The integrity of the coupling of the pneumaticport through the conical adapter to the pneumatic tubing 110 may beverified through the removable access piece 112. The removable piecethen may be closed to help keep unwanted noise from the ear.

FIG. 3 illustrates an implementation of the noise attenuating techniqueusing a piezoelectric transducer. Previously described features willonly be repeated as necessary. An ear cup 310 is adapted to fit over anear. A pad 316 is attached to the ear cup to provide a cushion for theuser of the headset and to help dampen sounds. The cushion may be made,for example, of a foam material. A sound absorbing foam 314 may bedisposed inside the ear cup 310. A piezoelectric transducer includes apiezoelectric substrate 302 disposed in a piezoelectric enclosure 304.The audio output of an audio transducer (not shown) may be coupled bywires 312 to the piezoelectric transducer, which, in turn, may couplethe audio output to the pneumatic port 106 and then through the earinsert that is inserted into the ear canal. The adapter 104 can be usedto retain both the pneumatic port and the piezoelectric transducer inproximity with one another. In an implementation, a removable accesspiece 306 can provide an opening in the ear cup to provide access to thepiezoelectric transducer 306, adapter 104, pneumatic port 106 and earinsert 102.

FIG. 4 is an implementation of the noise attenuating technique in astethoscope-type headset assembly 400. As described above, ear inserts102 are inserted into the ear canal. The stethoscope-type assembly,through pneumatic tubing 404, couples output sounds from an audiotransducer (not shown) to the pneumatic ports 106. A stethoscope tubingsupport 402 may hold the pneumatic tubes 404 together and may be made ofa semi-rigid material that can provide a spring pressure to urge the earinserts 102 into the ear canal. Ear inserts 102 have a through-hole andare adapted to fit into an ear canal. The pneumatic port 106 is disposedin the through-hole. Adapters 506 may be used to guide the pneumaticports 106 into the pneumatic tubes 404. The stethoscope assembly mayprotrude from the user's head less than a headset using an ear cup. Thistype of assembly may be appropriate for users having a large head orears that do not fit in available ear cups.

FIG. 5 is a detail view of the attachment of the pneumatic tube 404 tothe pneumatic port 106. The adapter 506 may be used to couple thepneumatic port 106 to the pneumatic tube 404. In an implementation, theadapter may have a conical opening on a first end 508 to help guide andsupport the pneumatic port 106 into a yoke connector 502. The adaptermay comprise a gasket 510 such as an O-ring disposed in the adapter tosupport, retain or help seal the pneumatic port 106 in the adapter 506.A second end of the adapter 506 is sized to fit snugly into a first endof the yoke connector 502 so as to reduce sound losses in theconnection. Other connection arrangements may be used. The yokeconnector 502 has a right-angle bend so as to reduce the distance thatthe stethoscope-type headset protrudes from the user's head. Thepneumatic tube 404 is coupled into a second end of the yoke connector502 such that sounds carried by the pneumatic tube 404 are coupled tothe pneumatic port 106. Yoke clamps 504 may be used to secure thepneumatic tube 404 in the yoke connector 502.

The ear inserts 102 with the pneumatic ports 106 are inserted into theear canals of the user. The adapter 506 may be inserted into the firstend of the yoke connector 502 and the pneumatic tube 404 connected tothe second end of the yoke connector and secured by the yoke clamps 504.The adapter/yoke connector assembly may then be positioned onto thepneumatic port 106.

Other embodiments are within the scope of the following claims.

1-20. (canceled)
 21. A magnetically inert headset comprising: an earinsert having a through-hole and adapted to fit into an ear canal; apneumatic port disposed in the hole in the ear insert to receive audiblesound waves and couple the sound waves to the ear canal; a non-magneticmicrophone coupled to the headset; and a stethoscope-type yokeacoustically coupled to the pneumatic port to couple the audible soundwaves from a non-magnetic transducer.
 22. The headset of claim 21wherein the non-magnetic transducer comprises an audio transducerdisposed in a magnet room of a magnetic resonance imaging system. 23.The headset of claim 21 wherein the non-magnetic transducer comprises apiezoelectric transducer.
 24. The headset of claim 21 wherein thenon-magnetic transducer comprises an electrostatic transducer. 25-34.(canceled)
 35. A magnetically inert headset comprising: an ear inserthaving a through-hole and adapted to fit into an ear canal; a pneumaticport disposed in the hole in the ear insert to receive audible soundwaves and couple the sound waves to the ear canal; and astethoscope-type yoke acoustically coupled to the pneumatic port tocouple the audible sound waves from a non-magnetic transducer.
 36. Theheadset of claim 35 wherein the non-magnetic transducer comprises anaudio transducer disposed in a magnet room of a magnetic resonanceimaging system.
 37. The headset of claim 35 wherein the non-magnetictransducer comprises a piezoelectric transducer.
 38. The headset ofclaim 35 wherein the non-magnetic transducer comprises an electrostatictransducer.